Abstract [en]

Biodiesel is an attractive alternative fuel for diesel engines.The feedstock for biodiesel production is usually vegetable oil, pure oil or waste cooking oil, or animal fats

The most common way today to produce biodiesel is by transesterification of the oils with an alcohol in the presence of an alkaline catalyst. It is a low temperature and low-pressure reaction. It yields high conversion (96%-98%) with minimal side reactions and short reaction time. It is a direct conversion to biodiesel with no intermediate compounds.

This work provides an overview concerning biodiesel production. Likewise, this work focuses on the commercial production of biodiesel. The Valdescorriel Biodiesel plant, located in Zamora (Spain), is taken like model of reference to study the profitability and economics of a biodiesel plant.

The Valdescorriel Biodiesel plant has a nominal production capacity of 20000 biodiesel tons per year. The initial investment for the biodiesel plant construction is the 4.5 millions €. The benefits are 2 million €/year. The investment is possible to recuperate in less than 3 years. The biodiesel yield can up to 98% with catalyst in excess. The energy used for the biodiesel production is 30% less than the obtained energy from the produced biodiesel. Replacing petro diesel by the biodiesel produced in the plant, the CO2 reduction can reach the 48%. It means that 55 000 tons CO2 per year can be reduced

The production of biodiesel from sunflower oil and ethanol using sodium hydroxide as catalyst was performed in the laboratory and the results are discussed. The results are analyzed using the statistic method of Total Quality.

The effect of the ethanol/oil ratio and the amount of used catalyst on the yield as well on the properties of the produced biodiesel is studied. The measured properties of the biodiesel are density, viscosity and refraction. The ethanol/oil ratio influences on the biodiesel production. The yield of biodiesel increases with the ethanol/oil ratio. Regarding the influence of the amount of catalyst on biodiesel production in the studied condition is not possible to achieve a definitive conclusion. But a tendency showing an increasing of the biodiesel yield with the amount of catalyst can be appreciated.

The study of the evolution of the transesterification during time shows that a reaction time of one hour is sufficient enough in order to reach the highest yield of biodiesel.